Cavitation in water generally takes place at much lower negative pressure than predicted from theories. In this work

we try to stress the discrepancy from the influence of the dissolved gas on cavitation nucleation. By combining molecular dynamics simulation and thermodynamic analysis

we evaluated the lowering of surface tension as a function of density of gas molecules in gas clusters formed in aqueous solution. We found that the obtained surface tension of small gas clusters is much more substantially reduced than expected. The surface tension lowering and the non-ideality of gas molecules in the clusters are then taken into account in determining the nucleation of cavitation

and as a consequence

the required negative pressure for cavitation becomes comparable to experimental values. Thus

we give an alternative explanation for the discrepancy of cavitation pressure between experiment and theory

i.e

.

it is the substantially reduced surface tension for small gas nuclei

which have not been taken into account in theory

along with the ideal gas approxiamtion that induce its deviation from the experimental values.